We make war so that we can live in peace.
—Nicomachean Ethics, Book 10, 1177b 5–6
All our arts and enquiries, just the same as all our actions and choices, are thought of as trying to achieve some good. For this reason, we can correctly define the Good as “that which all things aim at.” Yet obviously there is a difference between the ends at which things aim. Some of these ends are activities, whereas some are results distinct from activities. Where the ends are distinct from the actions, the results are naturally superior to the activities. Because there are all kinds of arts, activities, and sciences, it is inevitable that they have all kinds of different ends as well. The end of medical science is health; the end of military science is victory; the end of economic science is wealth.
—Nicomachean Ethics, Book 1, 1094a 1
Human good turns out to be the active exercise of the soul in conformity with excellence or virtue, and if there is more than one excellence or virtue, in conformity with the best and most complete. But this activity must take place throughout a complete lifetime, for one swallow does not make a summer, any more than one fine day. Likewise, one day or a brief flight of happiness does not make a man completely blessed or happy.
—Nicomachean Ethics, Book 1, 1098a 16–19
Tragedy is the representation of an action that is worthy of serious attention, involves greatness, and takes place over an extended time yet is complete within itself ... portraying incidents which arouse pity and fear, so that such emotions are purged by the performance.
—Poetics, 1449b 24–28
He who studies how things originated and came into being, whether this is the state or anything else, will achieve the clearest view of them.
—Politics, 1252a 24–25
Thus it is clear that the state is a creation of nature. . . . And it is one of man’s characteristics that he alone possesses a sense of good and evil, justice and injustice, and such, and the coming together of living beings who possess this sense makes a family and a state.
—Politics, 1253a 2–18
The notion of the state is naturally prior to that of the family or the individual, for the whole must necessarily be prior to the parts. If you remove the whole man, you can’t say a foot or a hand remains, unless you look upon this as if it were made of stone—for it would only be dead. A thing is only understood to be what it is owing to its abilities and its power to perform them. And when it no longer has these abilities or power, it no longer remains the same thing, it merely has the same name. It is thus obvious that a city precedes an individual. For if an individual isn’t sufficient in himself to form a perfect government, he is simply to a city what other parts are to a whole. And anyone who is unable to live in society, or doesn’t need to because he is sufficient unto himself, must be either a beast or a god. Thus everyone has a natural impulse to associate with others in this way, and whoever founded the first civil society brought about the greatest good to humanity. In this way man is the finest of all living creatures, just as without laws and justice he would be the worst. For nothing is so difficult to eradicate as injustice perpetrated by force. But man is born with this force—which is both prudence and valor—and it can be used for both just and unjust purposes. Those who abuse this force will be the most iniquitous, lustful, and gluttonous beings imaginable. On the other hand, justice is what binds men to the state; for the administration of justice, which consists of determining what is just, is the principle of order in political society.
—Politics, 1253a 25–40
Democrats maintain that democracy is what the majority decide; those who favor oligarchies believe that those with the most wealth should decide. But both these ways are unjust. If we follow what is proposed by the few, we soon have a tyranny. For if one person possesses more than any others, according to oligarchical justice this man alone has the right to supreme power. On the other hand, if superiority of numbers is the criteria that prevails, injustice will be perpetrated by the confiscation of the property of the rich, who will be in the minority and thus have no say. The notion of equality, to which both parties will subscribe, must therefore be taken from the definition of right which is common to both.
—Politics, 1318a 19–28
The objects of mathematics are not substances in any higher sense than things. They are only logically prior, not prior in being, to sensible things. Mathematical entities can in no way exist on their own. But since they cannot exist in perceivable objects either, they must therefore not exist at all, or exist in some special way which does not imply independent existence. For “to exist” can mean many different things.
—Metaphysics, 1077b 12–17
Where natural bodies are concerned, some have life and some do not. That is to say, some are able to nourish themselves, to grow and to decay. Thus every living natural body, which must be substance, must also be a complex substance. But since it is a body of a particular kind—that is to say, it has life—the body cannot be soul. For a body is a subject, not something predicated to a subject, and is thus matter. The soul is therefore substance in the sense that it is the form of a natural body, which potentially has life. Substance in this sense is actuality. In this way the soul is the actuality of the living body. But actuality has two senses, which are similar to the possession of knowledge and the use of knowledge. The actuality of which we are speaking is similar to the possession of knowledge. For both sleeping and waking require the presence of a soul—and waking is like the use of knowledge, whereas sleeping is similar to the possession of knowledge without using it.
—De Anima, 412a 17–26
It is obvious that there are causes, and many of them. These are discovered when we begin asking: “Why did this happen?” This leads us back to several basic questions. When faced with unchangeable things, we are left asking: “What is it?” For example, in mathematics it all comes down to the definition of a straight line or number or some such. Or in other cases we might be led to ask: “What brought about this change?” As for instance in: “Why did these people go to war?” The answer here could be: “Because of border raids.” Or it could be because what the thing itself is for: in other words, they fought for dominion. In another category, where things come to be, their cause will be matter.
Evidently these are the causes. There are several different types of causes, and anyone who wishes to understand nature should know how to uncover them. In fact, there are four different types: matter, form, whatever brings about the change, and whatever the thing is for.
—Physics, 198a 14–24
Thus motion, being eternal, if there is a prime mover it too must be eternal ... and here it is sufficient to assume there is only one mover, the first to set in motion stationary things, and this being eternal will be the principle of motion for all other things.
—Physics, 259a 7–14
Aristotle wrote and thought so originally about so many things that he was bound to get a few of them wrong:
People whose nostrils have thick extremities are lazy, just like cattle. Those who have thick ends to their noses are insensitive, just like boars. On the other hand, people who have sharp-ended noses are easily angered, much like dogs. However, those with round flat ends to their noses are magnanimous, in the same way as lions. People with thin tips to their noses are like birds; but when their nose is hooked and juts out straight from their forehead they are liable to shameless behavior (just like ravens).
—Physiognomics, VI 28–36
Aristotle did much to establish scientific investigation and categorization. His achievements are astonishing, especially when one considers much of the current evidence and material in this field, some of which he recorded:
In Arabia there is said to be a species of hyena which paralyzes its prey by its mere presence. If this hyena steps into the shadow of a man, it not only paralyzes him but renders him completely dumb.... There are two rivers in Euboea. The cattle that drink from the one called Cerbes turn white, and those that drink from the one called Neleus turn black. . . . The river Rhenus flows in the opposite direction to other rivers, running to the north where the Germans live. In the summer its waters are navigable, but in the winter it is frozen with ice, so that the people can walk on it like land.
—On Marvelous Things Heard, 145, 168
For centuries many of Aristotle’s contributions to philosophy were considered sacrosanct. His truths were “eternal truths” which could never be denied. But the advent of modern philosophy led to the gradual discarding of Aristotelian thought. Surely his most important contribution, logic, would last forever. Then came Nietzsche, and even this was called into question:
We cannot both affirm and deny the same thing. This is a subjective empirical law—nothing to do with logical “necessity,” only of our inability to do it.
In Aristotle’s view the law of contradiction is the most certain basic principle of them all. It is the ultimate and most fundamental principle upon which all demonstrative proof rests. The principles of every axiom depend upon it. Yet if this is really the case we should perhaps examine more thoroughly what presuppositions are already involved here. Either it says something about actuality, about being, as if we already knew it from another source; that is, as if opposite attributes could not be ascribed to it. Or it means: opposite attributes should not be ascribed to it. In which case, logic would not be an imperative to know the truth, as formerly supposed, but merely an imperative to organize a world that we could look upon as the true one.
Thus it remains an open question—Do the axioms of logic precisely match reality? Or are they simply a means and method for us to create a concept of “reality” that suits us? As already indicated, to agree with the first question we would have to possess a previous knowledge of being (i.e., one prior to our use of, and in no way involved with, logic). And this is certainly not the case. The proposition (the one that forms the law of contradiction) thus involves no criteria of truth. It is simply an imperative saying what should count as true.
—Nietzsche, Will to Power, Sec 516
Logic thus becomes the morality of our way of viewing and perceiving the world—the ethics of our epistemology. To deny it is “wrong, ” not in a factual sense but in a moral sense. Our entire notion of truth—logical, scientific, religious, the need to tell it socially, and so forth—are thus in the same category. They are systems by which we live, which are of use and benefit to us. They are not based upon what actually happens but upon what is useful to us and fits in with how we choose to view the world.